Epidemiological studies on general populations estimate the prevalence of temporomandibular joint internal derangements (TMJ ID) to be between 14% to 44%. Arthrotomographic investigation in conjunction with cephalometrically corrected TMJ tomography has become a standard tool for diagnosis of TMJ ID. The purpose of this study is to determine if diagnostic criteria using a combination of parameters from (1) history of present problem, (2) clinical examination and (3) tomography (without arthrotomography) are used to establish the presence and stage of TMJ ID, there will be good percent agreement between this diagnosis and the diagnosis rendered by arthrotomography of the TMJ. Sixty sequential consenting adults referred to Methodist Hospitals for routine arthrotomographic evaluation will be examined, complete a questionnaire and have TMJ tomograms taken prior to arthrography. The history included occurrence of (1) TMJ noises, (2) locking, (3) limitation of opening. The clinical examination measures for (1) maximum jaw opening, (2) maximum left and right lateral jaw movements, (3) lateral deviation on opening, (4) S-curve deviation on opening or closing, (5) reciprocal clicking in the TMJ and (6) TMJ crepitation. Evaluation of tomography will include: 1. range of motion of the condyle, 2. whether degenerative changes are present in the osseous structures of the TMJ. Diagnostic criteria for each stage of TMJ ID will be established in two ways: (1) a prespecified set based on a literature review and (2) a set derived from discriminate analysis of individual parameters. The hypothesis is that there will be a minimum agreement of 80% between the diagnosis rendered by using the diagnostic criteria of these two methods and the diagnosis arrived at by arthrotomography of the TMJ. If this proves true, then arthrotomography, which is an expensive, invasive and painful procedure, can be reserved for (1) presurgical screening/treatment planning, and (2) to fulfill the requirements of hospitals for surgical criteria that the indicated surgery is valid.